A comparison of battery and phase change coolth storage in a PV cooling system under different climates

Abstract

Energy storage in PV cooling systems is desirable to supply on-site loads during solar outages. Current storage methods of such systems typically use battery storage to store surplus electricity generated by solar panels or coolth thermal energy storage (CTES) to store excess cooling capacity produced by an electric-driven chiller. This study compares three cooling system configurations – no energy storage, with a battery storage, and with a phase change CTES, for a residential building under the climate of Shanghai, Madrid and Brisbane. System simulation of each configuration was conducted using TRNSYS. A CTES component was programmed externally using effectiveness-NTU method. Both energy storage methods were compared with regard to energy change during a summer day, power consumption and primary energy saving ratio (PESR) during the cooling season. In addition, performance of a single battery and a single CTES were evaluated under various operational conditions. The results showed good energy performance of both storage cases. The PESR of battery case and coolth storage case were 2.8 times and 1.9 times higher than that of a reference case with no energy storage.